Drive trains of this general type are typically used in motor vehicles. They include an internal combustion engine, a transmission, and a drive for driving the motor vehicle. Torsional-vibration damping systems that include one or more torsional-vibration dampers, for instance, are known in the art for isolating and damping torsional vibration of the internal combustion engine. The torsional-vibration dampers are preferably arranged on the crankshaft, or on a transmission input shaft of the transmission, and can be divided flywheels, torsional-vibration dampers in clutch discs of a friction clutch arranged between the crankshaft and the transmission input shaft and the like, and are known, for example, from the documents DE 37 03 123 A1 and DE 34 42 705 A1. Furthermore centrifugal pendulums have become known in the art as torsional vibration dampers, for example from the document DE 10 2010 005 599 A1. These centrifugal pendulums form a rotary-speed adaptive torsional-vibration damper by means of pendulum masses that may pivot to a limited extent relative to a pendulum flange received with the crankshaft or transmission input shaft. Moreover, combinations of centrifugal pendulums and the aforementioned torsional-vibration dampers are known, for example, from WO 2011/110153 A1, DE 10 2010 018 941 A1, and DE 10 2010 022 252 A1. The torsional-vibration damping system is adapted to the torsional-vibration behavior of the internal combustion engine, for example to the vibration order thereof. For four-stroke engines with four cylinders the vibration orders equal two and for four-stroke engines with two cylinders, the vibration orders equal one, for example.
DE 100 36 720 A1, for instance, discloses an internal combustion engine wherein a predefined number of cylinders can be switched off to save energy in driving situations that have low load requirements, and can be switched back on when a corresponding torque is required. The result is an internal combustion engine with two modes of operation in one drive train with different vibration orders, and thus different torsional-vibration behavior.
An object of the present disclosure is to provide a drive train that achieves an improved torsional-vibration behavior in both operating states of the internal combustion engine as a result of an adaptable torsional-vibration system.